Engine starter accessory



April 8, 1969 L. J. H-AMMAN 3,437,033

ENGINE STARTER ACCESSORY Filed Sept. 30, 1965 Sheet L of 4 INVENTOR i LYLE J HAMMAN ATTORNEYS April 8, 1969 L. J. HAMMAN 3,437,083 I ENGINE STARTER ACCESSORY Filed Sept. 30, 1965 Sheet 2 zaw-naw-r W7 l r I 'JG.3

Hy 24'' It 8 l I i /26 N "IG.9 INVENTOR LYLE J. HAMMAN ATTORNEYS April 8, 1969 J. HAMMAN 3,437,083

ENGINE STARTER ACCESSORY Filed Sept. 30, 1965 Sheet of 4 I 1 5! mm 64 4 F 62 I r 42 2 I z A 50 w F164 1 "52 #464 m4 J m Z4 m a ry INVENTOR LYLE J. HAMMAN ATTORNEYS April 8, 1969 L. J. HAMMAN ENGINE STARTER ACCESSQRY Sheet of 4 Filed Sept. 30, 1965 INVENTOR LYLE J. HAMMAN BM ATTORNEYS United States Patent U.S. Cl. 123-479 2 Claims ABSTRACT OF THE DISCLOSURE The invention takes the form of a portable electric starter for internal combustion engines, the starter having a coupling with a crankshaft upon relative axial movement between the starter and the crankshaft, the starter and the engine having torque resisting means coupling one with the other during relative axial movement.

The present invention relates to improvements in starter systems for internal combustion engines.

With the increasing use of power lawn mowers, power snow plows, garden and lawn tractors, and the like, equipped with twoand four-cycle internal combustion engines in the general range of two to ten horsepower, the starting of such engines under year-round temperature and humidity conditions, especially by inexperienced and less muscular members of a family, has presented an increasing problem.

In general, the ease of starting of relatively small internal combustion engines is dependent, to a great extent, on the rate of rotation and the duration of the cranking period. To improve the rate of rotation of cranking that is possible through the use of a starter rope would upon a spool or pulley carried on or connected to the crankshaft of the engine, impulse starters were developed and introduced on the market to provide a sudden release of cranking energy stored in a spring. To extend the duration of the cranking period, the use of portable power tools, such as electric hand drills, has been proposed for use on engines of the type described above in order to overcome the difiiculties of starting the same with loose pull ropes, recoil rope starters, and the like.

The initial cost and the weight of electric starting mechanism has greatly restricted the permanent mounting of such equipment on lawn and garden equipment. In an attempt to overcome the weight problem and the initial cost of a storage battery, alternating current starter motors have been mounted on the engine and connected with the household electric circuit for starting purposes. Such an arrangement is disclosed, for example, in U.S. Patent No. 2,881,352.

Regardless of the type of starter mechanism that is permanently mounted on engines of the type described, it has been found that the vibrations and shocks to which the starter mechanism is subjected while inoperative but during operation of the engine, and the use of the equipment being powered by the engine, is extremely detrimental to the operational life of the starter mechanism, particularly where the use of the equipment subjects the starter mechanism to dirt and dust and other abrasive materials. For example, it has been found that clutch dogs used in the starter mechanism are capable of withstanding thousands of engine starts on bench testing and provide only a few hundred starts when the starter is being used on a power lawn mower and subjected to vibrations and shocks of the mowing equipment and the abrasive environment in which the mowing equipment operates.

3,437,083 Patented Apr. 8, 1969 According to the present invention, it is proposed to provide a starter for engines of the, type described which may be safely and effectively used by any member of the family to start small internal combustion engines used about the home and farm.

In one form the invention contemplates a starter system in which the initial starting of the engine is accomplished by a detachable power starter with subsequent starting of the engine in the yard or field for that day being accomplished by manual means. A starter system is also contemplated in which no manual means are provided and all engine starts are accomplished solely by a detachable power starter.

iMore specifically, the present invention contemplates a starter system in which a portable electric starter mechanism is provided which is light and relatively inexpensive, yet is capable of cranking engines up to ten horsepower at rates in the order of 500 to 1000 rpm. for suflicient periods of duration to both adjust and start the engine under almost any condition. To prevent damaging the starter mechanism when the engine starts, an overrunning clutch mechanism is preferably imposed between the engine and the starter mechanism. Also, to enable the engine starter to be used by all persons, regardless of age, strength or experience, the proposed starter system contemplates an arrangement for completely removing the starting torque from the person handling the starter mechanism. In one form the invention proposes means which permits operation of the starter mechanism only when the mechanism is associated with the engine in such manner as to prevent any torque reaction being transferred to the person applying the starter to the engine for starting purposes.

Thus, an object of the invention is to provide an improved starter system on equipment of the type described which is relatively inexpensive, extremely effective and may be safely used by any member of the family.

Another object of the invention is to provide a starter system for small engines involving the portable, detachable electric power unit having novel torque absorption and rotational connections with the engine, the connections being preferably effected by relative movement between the engine and the unit taking place along the longitudinal axis of the crankshaft.

Another object is to provide a starter system which may be readily adapted to existing lawn and garden power equipment, and the like, yet possess the advantages set forth in the previous paragraph.

A still further object of the invention is to provide a portable, detachable starter unit for internal combustion engines in which relative axial movement between the starter mechanism and engine, upon engine starting, may take place relatively free of rotational reactions and starter drag.

A still further object is to provide a starter system in which a portable electric starting unit has clutch mechanism for selectively connecting and disconnecting the unit to and from the engine and a torque arm for selective engagement with structure capable of absorbing or resisting the torque reaction of the starter and associated with structure fixed relative to the engine mounting.

Another object is to provide a starter system in which a completely separate and independent portable electric power unit is manually and bodily moved into cranking association with the engine, the movement of the unit into cranking position acting to bring portions of the engine and unit into torque resisting relation as well as acting to close at least a portion of the electrical circuit of the unit.

Another object of the invention is to provide, in combination with an electric starter unit and the crankshaft of an engine, clutch mechanism having one portion on the unit and another portion on the crankshaft, the portions being freely and relatively moveable along the axis of rotation of the crankshaft into and out of nested relation with each other, the clutching area of the portions being disposed in circular paths concentric with said axis and located in a plane normal thereto.

A still further object resides in the improvement of the previous paragraph in which the clutch portions define an overrunning clutch mechanism with one portion being in the form of a cylindrical post attached to the crankshaft and the other portion of the clutch attached to the unit being in the form of a cylindrical-like recess having the post-engaging surface defined by a plurality of radially and circumferentially movable clutch members, the clutch members having an association with the cylindrical surface of the post characterized by the fact that the members maintain continuous contact with the post surface throughout the cranking cycle irrespective of the fluctuation in input energy required due to the compression and expansion of the fuel charge of the engine.

A further object resides in the improvements in starter systems for small internal combustion engines wherein a separate, independent and bodily removable portable starter unit is centered and supported upon a vertical post on the engine for cranking the same about an axis of rotation coinciding with the vertical axis of the post, the unit having means radially disposed to its post receiving portions for engaging means on the engine radially disposed to vertical axis of the post to resist the torque relation of the unit.

A further object is to provide a separate, independent and portable electric starter unit for small engines in which the electrical circuit for the unit may only be closed with the unit correctly positioned upon the engine and the torque resisting coupling between the unit and the engine fully established.

These and other objects and advantages of the present invention will appear in more detail from the following specification and claims.

In the drawings,

FIG. 1 is a side elevational view of an engine which has been adapted to the starter system of the invention, the power unit being shown vertically aligned with the torque and rotational coupling means on the engine,

FIG. 2 is a partial view of FIG. 1 showing the power unit lowered into starting position on the engine.

FIG. 3 is a fragmentary vertical section through the torque and rotational coupling means on the engine and power unit with the coupling means aligned as shown in FIG. 1,

FIG. 4 is a fragmentary vertical section of the coupling means of FIG. 3 with the means in starting position,

FIG. 5 is a section taken on line VV of FIG. 4 showing the adjustment structure for the torque sleeve in the torque arm,

FIG. 6 is a side elevational view of the power unit with one part of the two-part casing which embraces the electric motor being shown removed,

FIG. 7 is a plan view of the torque resisting means on the engine,

FIG. 8 is a sectional view taken on line VIIIVIII of FIG. 4 of the overrunning clutch of the rotational cou pling means on the power unit and engine,

FIG. 9 is a fragmentary vertical section of a modification showing the starter system adapted to a rope starter hub on the engine crankshaft,

FIG. 10 is a view similar to FIG. 9 of a further moditfication showing a cone clutch coupling between the power unit and the engine,

FIG. 11 is a still further modification showing the principles of the invention adapted to starting from engagement with the engine flywheel, and

FIG. 12 is a side elevational view of a further modification.

In FIGS. 1 and 2 an internal combustion engine 10 is shown mounted on a rotary lawn mower 12 for driving a horizontally disposed blade 14 about the vertical axis a-a conforming to the axis of rotation of crankshaft 16 and the blade 14. A side mounted starter 18, such as disclosed in US. Patent No. 2,024,780, as shown mounted on the engine 10 and adapted to engage the flywheel 20 to start the engine 10 in a well-known manner.

The starter system of the present invention has been adapted to the engine 10 of FIG. 1 through the application of a torque pin 22 to be attached to the fixed structure of the engine 10 and the application of a rotational coupling part and centering post 24 to the threaded stud 26 on the upper end of the crankshaft 16. Cooperating with the pin 22 and post 24 is a portable electric power starting unit 28 which is completely independent of the engine 10 and is provided with a rotational coupling part 30 for engaging over the post 24. The unit 28 also comprises a fixed torque sleeve 32 for receiving, within its bore 34, the pin 22 fixedly supported on the engine 10. With the portable unit 28 plugged into a suitable electrical outlet and positioned on the engine 10, as shown in FIG. 2, the engine 10 is cranked by unit 28 upon closing the switch 36. After starting the engine 10, the unit 28 is removed from the engine.

It is anticipated that the portable unit 28 will be used to adjust and start the engine 10 when the engine is cold or otherwise difficult to start. Thereafter, with the engine 10 warmed up and in good operating adjustment, the engine 10 will be started by using the starter 18 in the usual manner thus avoiding the return of the lawn mower 12 to a source of electricity where the unit 28 may again be used to restart the engine after the initial starting operation.

To more specifically describe the illustrated embodi ments of the invention, in FIGS. 3 and 7 the torque pin 22 is shown mounted on one end of a rigid arm 38 detachably connected at the other end by a bolt 40 to a fixed rigid portion of the engine 10. The hole 42, which receives the bolt 40, may be one especially drilled to receive the bolt 40 or the hole 42 may be one provided in existing equipment, for some other purpose, to which the invention is being adapted. For example, the hole 42 may be one of several holes originally used to mount a recoil or impulse starter on existing equipment with such equipment being converted to the starter system of the invention by merely removing the recoil or impulse starter mechanism and using the unit 28 for all engine starting purposes. With the pin 22 supported in the manner of FIGS. 3 and 7, the arm 38 may be rotated through an arc about the axis of the hole 42 necessary to conform the spacing of the pin 22 and post 24 to the spacing of the sleeve 32 and coupling 30. Thus, the starter system of the invention may be readily adapted to existing equipment by merely bolting the arm 38 through an existing hole 42 and substituting the threaded post 24 for the usual nut employed to secure the flywheel 20 to the crankshaft 16. The post 24 is shown with a cylindrical portion 44 and a hexagonal portion 46 to enable the post 24 to be applied to the stud 26 with a wrench.

Referring to FIGS. 4 and 6, the power starter unit 28 comprises an electric motor 48 encased in a housing 50 which, preferably, takes the form of a pair of similar cast or molded sections 52 and 54. The drive shaft 56 of the motor 48 projects into a cast gear case 58 and carries a relatively small pinion 60 which meshes with the gears 62 on shafts 64. Pinions 66, driven by the shafts 64, in turn mesh with a ring gear 68. Coupling part 30 has an enlarged flange portion upon which the ring gear 68 is mounted and rotated as a unit. Flange portion 70 rotates in a bearing 72 collectively defined by the housing sections 52 and 54.

In practice, the motor 48 is preferably volt A.C. rotating at 8000 rpm. at no load. The gear train in the case 58 reduces the rotation of the motor 10 whereby the ring gear 68 and coupling part 30 are rotated at 1000 r.p.m. With the motor 48 capable of delivering to the part 30 a torque in the order of 150 pounds, at stalled conditions, such a motor and gear reduction has been found capable of starting engines up to HP. at minus F. The crank speed for satisfactory starting of the engine 10 is in the order of 500 to 1000 r.p.m. Upon starting, the speed of the engine 10 is in the order of 1500 to 2000 r.p.m. It will be readily appreciated that the engine 10, upon starting, should not be given the opportunity of driving the shaft 56 through the gear train at speeds in the order of 16,000 r.p.m.

The initial cost of an electric motor and gear-reduction mechanism capable of being driven by the engine 10 upon starting at speeds in the order of 16,000 r.p.m. without detrimental effect would more than double the cost of the power unit 28 when compared with that which has been found to be entirely satisfactory when used solely for starting engine 10 and the power unit 28 is removed from the engine without being driven at detrimental speeds by the engine or subjected to the vibrations of the engine 10 in use or to the abrasive environments in which the engine 10 is operated.

Rigidly associated with the gear case 58 is a torque arm 76 having a split bore 78 in which the torque sleeve 32 is closely fixed for axial adjustment. As more clearly shown in FIG. 5, an adjustment screw 80 is provided for selectively clamping the arm 76 upon the sleeve 32, all in a well-known manner.

Referring to FIG. 6, the motor 48 and arm 76, rigidly attached thereto, are embraced within the housing defined by the similar sections 52 and 54 each of which constitutes one-half of the housing. As shown, the section 54 has been removed with the section 52 defining one-half of the chamber 86 in which the arm 76 and motor 48 are disposed. The upper portions of the sections 52 and 54 define the handle portion 88 of the power unit 28 and provide a recess 90 in which the on and off switch 36 is located for actuation by the thumb of the person operating the unit 28. A further recess 94 is provided by the sections 52 and 54 into which the arm 76 projects. Above the arm 76 a switch assembly 96 is housed in the recess 94 for relative movement at the time the sleeve 32 is adjusted in the arm 76, the unit 96 being attached to the inner end of the sleeve 32 and having an on and off plunger 98 projecting into the bore 34 to be engaged by the upper end of the torque pin 22 to move the plunger 98 from its normally off position to an on position.

The electrical circuit for the motor 48 includes the conductors 100 and 102. The conductor 102 placing switches 36 and 96 in series and requiring both to be moved to an on position in order to energize the motor 48. It will be appreciated that axial adjustment of the torque sleeve 32 will permit the plunger 98 to be adjusted to a position closing the switch 96 only in the event the unit 28 is in the position of FIG. 2, in which position the coupling parts 24 and are fully engaged as are the torque pin 22 and sleeve 32, whereby a safe and stable association between the power unit 28 and engine 10 is assured at the time the operator actuates the switch 36.

While the structure of the clutch mechanism between the unit 28 and engine 10 for starting purposes may take many forms, preferably such mechanism takes a form that (1) provides support for the unit 28 along the axis aa of FIG. 1, (2) facilitates removal of the unit 28 upon engine starting, and (3) permits the engine 10 to overrun the unit 28 to prevent driving of the unit 28 by the engine 10. Mechanism having these preferred characteristics is shown in FIG. 4 where the part 30 has a cup 104 firmly coupled to the part 30 in any suitable manner, as by brazing. A cage 106, carrying cylindrical rollers 108, is disposed in the cup 104 and retains the rollers 108 in assembled relation within the part 30. The area of the cup 30 opposite the rollers 108 is provided with a series of axially extending, inwardly inclined surfaces 110 separated by axially extending ridges 112. Spring component 114 and part of the cage structure 106 are associated with each roller 108 and continuously urge the rollers 108 up the inclined surfaces 110 to impart a slight, radially inward movement to each roller 108 to wedge the same between the cylindrical portion 44 of the post 24 and the cup 104 to couple the driver part 30 to the driven post 24 in a well-known manner when the part 30 is being rotated as a driver. When the part 24 is being rotated by the engine 10, on starting, at a higher rate than the part 30 is being driven by the motor 48, each roller 104 moves down its inclined surface 110 away from its ridge 112 and into a roller bearing position between the cup 104 and the post 24.

The top 116 of the post 24 is radiused, as are the ends of the rollers 108, to enable the driver part 30 to be readily lowered into position on the post 24, the telescoping movement of the part 30 and post 24 slightly shifting the rollers 108 along the surfaces 110 to accommodate the cylindrical-like socket defined by the rollers 108 to the cylindrical portion 44 of the post 24, yet provide a stable piloted support of the starter unit 24 on the engine 10 capable of giving the unit 28 upright support along the axis aa of FIG. 1.

When the engine 10 is started, the overrunning action will shift the rollers 108 down to surfaces 110 to enable the unit 28 to be readily lifted from the post 24. However, the unit 28 is acting as a driver for the post 24 for cranking the engine to start the same or to keep the engine running; the wedging action of the rollers 108 between the cup 104 and post 24 will hold the unit 28 firmly coupled to the engine 10 and resist relative separation along the axis a--a.

To supplement the piloted support of the unit 28 along the axis aa on the post 24 and to remove the torque of the unit 28 from the operators hands, the torque sleeve 32 has a close sliding fit with the torque pin 22. For facilitating the insertion of the unit 28 on the pin 22 and post 24, one of these elements may project slightly above the other, as shown in FIG. 3, wherein the pin 22 enters the sleeve 32 in advance of the cylindrical portion 44 of the post 24 being received within the part 30. When the part 30 is rested on the enlarged nut portion 46 of the post 24, the pin 22 has been extended into the sleeve 32 a sufiicient distance to move the plunger 98 from its of position to its on position. When the operator actuates the switch 36, the unit 28 having been correctly applied will now crank the engine 10 with both the torque and the weight of the unit 28 being completely removed from the operator. It will be appreciated that the safety switch actuated by the plunger 98 may be omitted from the electrical circuit of the unit 28, if desired. However, it is deemed desirable to render the unit 28 inoperative until it is correctly positioned upon the engine 10. This is one of the features of the invention which enables the same to be safely and easily employed by women and children to start small engines used about the home and yard.

The present invention may be readily adapted to engines which are not equipped with side-mounted starters of the typejllustrated in FIG. 1. For example, the engine 10' of FIG. 9 is shown with a conventional cup 118 attached to the crankshaft 16' on which the starter rope is wound in a well-known manner. The post 24', corresponding to the post 24 of FIG. 3, is shown threaded on the stud 26' and holding the cup 118 to the crankshaft. Starter unit 28 may be applied to the post 24' in the same manner as heretobefore described in regard to its application to the post 24.

In lieu of overrunning clutch shown associated with the part 30 of FIGS. 3, 4 and 8, other forms of clutch mechanism may be used without departing from the basic conception of the invention. FIG. 10 shows a conventional cup 118' for a starter rope in which the clutch part 120 with a conical bore has been bonded, or otherwise secured, in position. Driver part 30', corresponding to part 7 30 of FIG. 1, is shown with a conical clutch part 122 which is lowered into driving position with the part 120.

FIG. 1 shows the adaptation of the invention to an engine having a side-mounted starter. In FIG. 11 the principles of the form of the invention illustrated in FIG. 1 are shown adapted to flywheel starting for use on engines equipped with the conventional recoil and impulse starters connected to one end of the crankshaft, in a well-known manner. As shown, the teeth of the flywheel 20' of the engine are engaged by the bevel gear 124- mounted on a suitable overrunning clutch mechanism carried on the part 30" of the starter unit 28. A bracket 12x6, attached to the engine 10 beneath the flywheel has a torque pin 22' and a pilot post 24". Pin 22' is received in the torque sleeve 32 while the pilot post 24" enters the bore 128 of the part 30" with a close sliding fit. When the unit 28 has been correctly positioned on the torque pin 22' and the pilot post 24", the plunger 98 will be moved to its on position to close the safety switch of the electrical circuit of the unit 28' in the same manner as described in regard to the unit 28 of FIG. 1.

When the safety switch 96 is not to be employed as a functional feature of the invention, you may dispense with the molded housing parts 52 and 54. Also, the torque resisting sleeve 32 will not be required with the switch 96 eliminated and a simple hole in the torque arm 76 may be substituted to receive the torque pin 22. With such an arrangement, in lieu of the handle 88 being a part of the housing, the handle would be directly attached to the motor 48 in the manner of the handle of a portable electric drill.

In FIG. 12 is shown a starter unit 28 modified as suggested in the preceding paragraph. The electric motor 48 has the handle 88 attached at one end. At the opposite end of the motor 48' the cast casing 58 for the gearreduction mechanism is attached to a reduced portion of the casting. The torque arm 76' is integral with the casing 58'. Driver clutch part 30' is carried by a ring gear (corresponding to the gear 68 of FIG. 4) having a bearing in the flanged ring 128 removably attached to a reduced portion of the casing 58. A hole 130 in the torque arm 76' is adapted to receive the torque resisting pin 22 shown in FIG. 1, while the driver part 30"" is adapted to engage and drive the driven part 24. Operation of the motor 48' is controlled solely by the single switch 4 I claim:

1. A starter system for relatively small internal com bustion engines, comprising an engine having fixed structure and a crankshaft, driven means rotatable with said crankshaft, first torque resisting means on said structure, a separate independently portable electric starter unit having rotated driver means for engaging with said driven means on bodily movement to rotate said crankshaft to start the engine, second torque resisting means on said unit engaging with said first torque resisting means with said driven and driver means engaged, said driver and driven means taking the form of overrunning clutch mechanism, said starter unit including electrical switch means mounted on said second torque resisting means, and means associated with said first torque resisting means for actuating said switch means when said driver and driven means are engaged.

2. A starter system for relatively small internal combustion engines, comprising an engine having fixed structure and a crankshaft, driven means rotatable with said crankshaft, first torque resisting means on said structure, a separate independently portable electric starter unit having rotated driver means for engaging with said driven means on bodily movement to rotate said crankshaft to start the engine, second torque resisting means on said unit engaging with said first torque resisting means with said driven and driver means engaged, said driver and driven means taking the form of overrunning clutch mechanism, one of said driver and driven means being in the form of a post and the other being in the form of a recessed member nesting with said post and piloted therein, said first and second torque resisting means on said unit and said fixed structure engaging with each other with said recessed member piloted on said post, said post and recessed member constituting said overrunning clutch mechanism.

References Cited UNITED STATES PATENTS 1,288,938 12/1918 Leonard. 2,123,711 7/ 1938 Callsen. 2,804,957 9/ 1957 Pechin. 2,831,352 4/ 1958 Elliott. 2,932,292 4/ 1960 Trotter. 2,968,920 1/ 1961 Wayne -3932 FOREIGN PATENTS 73 3,644 3/ 1943 Germany.- 402,992 3/ 1943 Italy.

LAURENCE M. GOODRIDGE, Primary Examiner. 

